The Primera División (First Division), officially named for sponsorship reasons as Liga BBVA Bancomer MX,[3] commonly referred to as Liga MX, is the top professional association football division of the Mexican football league system. Each season the league holds two tournaments; the Apertura, which starts in the summer, and the Clausura, which starts in the winter. As of 2012, the league comprises 18 clubs, with one being relegated every year (two tournaments) based upon their performance in the league over the previous three years. The top eight teams in the table at the end of the regular phase of the tournament qualify to the liguilla ("mini-league", or "playoff"). Up until June 2011, the league was divided into three groups. The group formatting was removed in favor of a single-table format.

The league is generally considered the strongest in North America, and among the strongest in all of Latin America. According to the International Federation of Football History and Statistics, the league currently ranks 13th worldwide[4] and was ranked as the 10th strongest league in the first decade of the 21st Century (2001–2010).[5]

Prior to the Liga Mayor, there was no national football league in Mexico, and football competitions were held within relatively small geographical regions. The winners of the Primera Fuerza, a local league consisting of teams near and around Mexican Federal District, was considered the national competition. There were other regional leagues such as the Liga Veracruzana, Liga Occidental of Jalisco and Liga del Bajío that also had notable clubs. Many club owners were not keen on the idea of establishing a professional league, despite paying players under the table. With the increasing demand for football, there was a sense of urgency to unite all the local amateur leagues in Mexico to progress as a football nation. The professional national league was finally established in 1943.[6]

When the Federación Mexicana de Fútbol Asociación (F.M.F.) announced the formation of the nation's first professional league, many clubs petitioned to join. The F.M.F. announced that 10 clubs would form the Liga Mayor (Major League). The first members of the league were founded by six clubs of the Primera Fuerza of Mexico City, two clubs from the Liga Occidental, and two members from the Liga Veracruzana managed by Eduardo Escoto.

Throughout the late 1950s and early 1960s, many small clubs faced economic difficulties which were attributed to the lack of international competition by Mexican clubs and an unrewarding league format. Like many South American and European clubs, Mexican clubs that placed high in the league standings could not afford to participate in prestigious international tournaments, such as the Copa Libertadores.

The 1970 World Cup held in Mexico was the first World Cup televised on a grand scale. The season following the FIFA World Cup, the F.M.F. changed the league format and established a playoff phase to determine the national champion. This was done to regenerate interest and reward teams that placed fairly high in the standings.

The playoff, called the Liguilla in Mexico, was played in different ways to get finalists to play two games that determine the champion. The regular way was by direct elimination rounds using the top eight teams of the table or, when groups existed, the top two teams of each group (along with the best performing third place teams). During some sessions, the best third placed teams were allowed to play a match against the lowest two second places in a repechaje in a chance to be promoted to the playoffs. This was eliminated as long as the calendar was modified to fit with the international compromises of both teams and Mexican National Team members.

Another way practiced to define finalists was by doing two groups of four teams and making them play round robin games in home/away stadiums so they can complete six games, with the top team in the group advancing to the Finals. This was used for a very short period of time as teams found out they did not have enough fight for three or four games.

The change in the rules affected teams that traditionally dominated the table, as talented teams that had not performed well in the regular season were able to perform successfully in the play-offs (Cruz Azul in the 70s, América in the 80s and Toluca in the 2000s).

From 1996 to 2002, the league followed a similar two-tournament schedule called invierno (winter) and verano (summer) but in 2002 to the 2010–2011 season they divided the 18 teams into three groups of six, called group one, group two, and group three. They remained in their respective groups throughout the two tournaments played that season. The qualification phase of the tournament lasted 17 weeks, with all teams playing each other once per tournament in a home and away series over both tournaments. The top two teams from each group and the two best third place teams qualified to reach the liguilla.

Liga MX is a single table of 18 teams that play two annual tournaments resulting in two champions per season. The season opens with the apertura tournament (opening tournament- running from July to December) followed by the clausura (closing - running from January to May). This format matches other Latin American schedules and correspond with FIFA's world footballing calendar, which "opens" in July/August and "closes" in April/May of the next year. Each team plays a different team each week, accruing points for wins and ties over the 17 week tournament. Based on these points, the top eight teams reach the liguilla phase of the respective tournament where a new champion is crowned.

This section is outdated. Please update this article to reflect recent events or newly available information.(February 2014)

The liguilla (Spanish for "little league") is the playoff phase of the tournament. This phase starts with eight qualifying teams and is played in the "tie" format in two-leg aggregate-score, similar to the quarterfinals and semifinals of the UEFA Champions League. The first six qualifying teams are the top 8 clubs in the regular season standings. The best two clubs on the General Classification Table who are not among the top two in their respective group round up the eight qualifiers. The Elimination bracket goes from an 8 team quarterfinal, to a 4 team semifinal, and a final. The Champion team is awarded the First division trophy, and the runner up is awarded a smaller version of the trophy as well. Each player receives a medal respective to their team's placement. The birth of La liguilla in 1970, modernized the league despite the disagreements between the traditionalists and the modernists. Clubs that were near bankruptcy were now better able to compete and generate profits.

At the end of a season, after the Apertura and Clausura tournaments, one team is relegated to the next lower division, Ascenso MX, and one team from that division is promoted and takes the place left open by the relegated team. Currently, the relegated team is determined by computing the points-per-game-played ratio for each team, considering all the games played by the team during the last three seasons (six tournaments). The team with the lowest ratio is relegated. For teams recently promoted, only the games played since their promotion are considered (two or four tournaments). The team promoted from Ascenso MX is the winner of a two-leg match between the champions of the Apertura and Clausura tournaments of that division. If a team becomes the champion in both tournaments, it is automatically promoted.

Each year, four teams from Liga MX qualify for the CONCACAF Champions League, the premier North American club competition. Generally, the Apertura and Clausura champions are placed in Pot A and the Apertura and Clausura runners-up are placed in Pot B. Should one or more teams reach the finals of both tournaments, Liga MX has implemented a formula for ensuring that both pots have one team that qualifies via the Apertura and one team that qualifies via the Clausura:[7]

If the same two teams qualify for the finals of both tournaments, those two teams will be placed in Pot A while the non-finalists with the best record in both the Apertura and Clausura will be placed in Pot B.

If the same team wins both the Apertura and the Clausura (facing two different teams in the finals of each tournament), then the Apertura/Clausura champions are placed in Pot A along with the Clausura runners-up, and the Apertura runners-up are placed in Pot B along with the non-finalists with the best record in the Clausura. This occurred most recently in the 2013–14 season (2014–15 CONCACAF Champions League) when León (2013 Apertura and 2014 Clausura champions) and Pachuca (2014 Clausura runners-up) were placed in Pot A, while América (2013 Apertura runners-up) and Cruz Azul (non-finalists with the best record in the 2014 Clausura) were placed in Pot B.

If the Apertura runners-up win the Clausura (facing two different teams in the finals of each tournament), then the Apertura and Clausura champions are placed in Pot A, and the Clausura runners-up are placed in Pot B along with the non-finalists with the best record in the Apertura. This occurred most recently in the 2011–12 season (2012–13 CONCACAF Champions League) when UANL (2011 Apertura champions) and Santos Laguna (2011 Apertura runners-up and 2012 Clausura champions) were placed in Pot A, while Guadalajara (non-finalists with the best record in the 2011 Apertura) and Monterrey (2012 Clausura runners-up) were placed in Pot B.

Each season, three Liga MX teams qualify for the Copa Libertadores, the premier club tournament for CONMEBOL (the South American football federation). The two teams with the best record in the Apertura excluding any team participating in that season's CONCACAF Champions League qualify for the second stage of the tournament. The Supercopa MX champions qualify for the first stage. Should the Supercopa MX champions qualify via the Apertura, the third best team in the Apertura will enter in the first stage instead.

In theory, all First Division clubs have the right to sell their own broadcast rights. What this means in practice is that the league is effectively divided between teams broadcast on Televisa, TV Azteca, Fox Sports, ESPN in México, and ESPN Deportes, Telemundo, and Univision in the United States. ESPN also own English broadcast rights in the United States. In previous years, when a team got relegated, the team that got promoted could only negotiate with the company that had the television rights of the team that got relegated. This agreement was cancelled in 2012 by the Liga MX when the promotion of Club León caused a television rights dispute with Televisa.[8] Currently, Club León matches are broadcast in Mexico by Fox Sports and other online media sites,[9] and in the USA by Telemundo.

Telelatino and Fox Sports World hold broadcasting rights in Canada; Fox Sports is the only network that holds rights to broadcast selected matches in United States and South America. Additionally, Televisa-owned networks Sky Sports and TDN hold exclusive broadcasting rights over selected matches throughout the regular season, although the majority of the most important ones are broadcast live on the national networks.

Most of the Saturday afternoon and evening matches broadcast by Televisa are shown primarily on Gala TV, though Saturday games played by Televisa's club America, are broadcast on Televisa's flagship network, Canal de las Estrellas. However, a blackout policy is usually applied in selected markets where affiliates are forced to air alternate programming during the matches, Sunday noon and afternoon games broadcast by Televisa are shown on Canal de las Estrellas. All of the games broadcast by TV Azteca on Saturday and Sunday are shown on Azteca 13; Friday's matches however are shown on Azteca 7. Tuesday, Wednesday and Thursday (known in Mexico as Fecha Doble or Double Date) matches picked by the national networks are shown on Canal 5 and Azteca 7 and the rest of the matches air on Sky Sports and TDN.

A recent rule, in effect since 2011, requires teams to play the final game of every season on Sunday during prime time, regardless of whether the team used to play local games in another timeslot, in order to capture more television audience during the game.

In the United States, Univision holds the rights to the home games of Club America, Chivas de Guadalajara, Pumas, Cruz Azul, Veracruz, Leones Negros, Atlas, Monterrey, Tigres, Jaguares FC, and Toluca. Azteca America has the home games of Santos, Puebla, Querétaro, Morelia, and Tijuana. Telemundo has Pachuca and Club Leon home games.